Telegraph system



l. H. BELL. TELEGRAPH SYSTEM.

APPLICATION man DEc.4. Isla.

1,484,767, l .Patented Nov. 7, 1922.'

" Alfy.

Patented Nov. 7, 1922.

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JOHN H. BELL, OF SOUTH ORANGE, NEW JERSEY, ASSIGNR T0 VES'IERN ELECTRIC COMPANY, INCORPORATED, OF NE'VYKYORK, N, -Y., A COBPORATONDF NEW YORK,

TELEGRAPH SYSTEM.

Application filed December 4, 1918. Serial No, 265,241.

To all 't0/wm 'it may concer/a.'

Be it known that I, donn lil. BELL, a citi- Zen of the United States, residing at South Oranoe, in the county oit Essex, State of New l'ersey, have invented certain new and useful improvements in Telegraph Systems, ot which the following is a full, clear, concise, and exact description.

rllhis invention lrelates to telegraph systenis and more particularly to so-called capacity systems, wherein a line conductor may have high electrostatic capacity characteristics as usually lencountered in submarine cable Working.

The ,principal object of this invention is to provide an improved organization ot apparatus for the transmission of telegraphic impulses in the torm ot ,so-called block7 signals. i

ln the telegraph art, it is commonly understood that in systems, wherein currents ot one polarity are employedior the transmission of dot signals and currents of the opposite polarity are employed 'tor the transmission ot dash signals, some gain in transn'iission may be had by providing that instead of sending a plurality of successive impulses ont.' current, which mayI correspond With either a group ot dot or a group ot dash signalsno interruption ot the current Will take place during the tran mission of a group or series of signals tor-med by impulses ot one andthe same polarity. Such continuous application oit' potcntial in substitution of a plurality of signals usually requiring a plurality of successivey impulses of like polarity is commonly referred to in the art as block signals. Signals of this character also servel to prevent so-called Wandering zero effects and when received through the operation oit a suitable tape recorder may be read by noting the length of tape Which may have passed through the receiver. In the case ot automatic repeaters block signals may be translated due toa polarized line' relay at a receiving station continuing on either socalled spacing or marking bias as Well understood in the art; y

In providing a system tor more effectively and efficiently handling telegraphic transmission ot this nature, the present invention provides an arrangement of relays interconnected in such a manner that they may serve as pole changers under the control of respective pluralities of brushes, which are7 in turn, controlled by means of a sultably notated or perforated transmitting tape. f

lhis invention is illustrated in the acconr panying drawing in which, for the sake of -clearness, only so much of a telegraphic transmitting system has been shown as will be necessary to a clear understanding of the features of the system.

:Referring to the drawing, Fig. l is a diagrammatic illustration of a transmittingr system in accordance with this invention, While F ig. 2 shows in theoretical form such signalling current curves as may serve to convey a clear understanding of the service resultssought in the present system.

ln describing the operation of this system, reference Will be had to the drawing, 1n which the reference character L indicates a duplezi'ed line or cable conductor, which may be understood as extending to a distant station (not shown). the cable stands normally connected through thecontacts tot a compound-Wound relay y l, and the contacts lll ot a second compoundwound relay ll toan earth connection 7. This earth connection is for the purpose of draining the cable of any currents which mayl remain therein due to the transmission ot signals,` as will presently appear. For the control ot' local circuits ot' the transmitting system, a local battery 20 .is connected common to a shaft 21 which carries a suitable metallic drum 22. A series of guide or feed pins 23, carried by `this drum, are arranged to mesh with a series of guide perfoi-ations Q5 extending centrally through the vlength of a transmitting tape 24. Perfora-` vtions 26-29, in this tape, are arrangedto i permit both brushes to make Contact with the 'drum 22 at proper instants; that is, the

brush SO may be just entering a perforation atthe instant the brush 3l Will be just leaving the same perforation. The spacing distance it'rom center to center of the pertorations 2x3-*28 is such that at proper moments, corresponding With intervals between The outgoing lead of successive impulses of like polarity, which in each case are represented by successive recurring perforat-ions, both brushes may be making contact with the drum 22 at the same time.v i. e., at the instant the brush 31 may be entering a perforation, as the perforation 27, the brush 30 will be just leaving a perforation, as the perforation 26, and engaging the tape sp-ace intervening between the two holes. In turn the brush 31` may be .just entering the perforation 28' at the instant the brush 30 is leaving the perforation 27. During the time the brushes may be in theposition shown in the drawing, current from battery 20' may flow: through the brush 3G and the operating windingw13 of the relay 11. On this relay the winding 12g is. so proportioned with respect to the energizing battery 2O that. while it may eX- ert sufficient force to retain the armature of this relay in an operated position, it will not, however', develop sufficient strengthto operate-or move the armature of this relay from its normal position. In thetransF mission example, assumedand represented by the perforations 26, 27, 28, 29 and 35 in the tape, it maybe pointed out that at the time the perforation 26 passed under the brush 31, current from the`battery-20l through this brush-and the winding12 of the relay 11 would not have caused the operation ofv this relay, sincefthe winding 12is proportioned to develop only sufficient strength to retain'the armature of the relay in its'operated position as described. When the first perforation 26 comes under the brush 30, however, a circuit will be completed from :the battery 2O through the winding 13 'of the relay 11 and therein develop sufhcient strength to operate thisre?.

lay. At an inst-ant just before theffirst perforation -26 passes from beneathithe brush 30, thereby causing disconnection of current through the winding 13, thebrush 31 will have entered the perforation y27 to establish current through the winding 12'.

whereby the armature of the relay 11 will beheld in its forward position. fDuring the time the relay 11 continues operated, la cirl cuit may-be traced from the earth connection 7 by way ofthe contacts 15 of the re-` lay 11 to the .positive pole ofra line-battery- 6, continuing through this battery land the normal contacts 1 of the relay 1'to the ca- As the tape advances, the brush 30 will enter the perforation 27 just before the brush, 31 leaves this perforation. therefore, current will continue through the Vholding just `before the perforation 27 leaves the brush 31 the brush 30 will have lalso entered this perforation and established current through the' operating winding 13 to continue the energization of the relay 11 during the period the tape intervening between the holes 27 'and 28 is passing underneath th'e holdingcircuit controlling brush 31. As the. perforation 28 passes beneath the brush 31 the holding winding 12 will receive current to lock the relay 11 while the brush 30 is traversing the tape between the perforations 27 and 28. Inturn the brush 30wil1 enter the perforation 28 before the brush 31 leaves this opening and current throughA the winding-13 will retain thev relay l11 operatedy until the perforationl28 passes from beneaththe brush 30, whereupon the relay 11 will. Jbe disconnected to permit its release.

`'From the foregoing description, it will be clear that during `the time the successive perfor-ations 26, `27 and 28 may be passing beneath the brushes 30 and 31 instead of three lseparat-cfne ative impulses'being iin-v brush- 3,7, thewperforation will 'permit current fromthe battery 20 to complete circuitthrough the winding 2 of the relay 1, this rel-ay will not be operated due to the fact that this marginal winding is so pro*l port-ioned that while it may serve'as a holding winding to retain the armaturel of this relay in its .operated position, lit will not develop suflicient strength to move the armature ofthisf relay from its normal position, themargins being similar to those already described vin connection with the winding 12 ofthe relay\11. Then the perforation 35 arrives under the brush 36, however, current from .the `battery 20 through the winding 3 will `cause the operation of the relay 1, and since, atsuch time, thebrushes 30iand 31- are insulatedion the tape inter` medi-ate the perforations 28 and 29, the relay11 will stand disconnected and therefore bein itsnormal position. The operation of the relay 1, inr responseto current through the winding 3, as established by the brush 36, :will complete a circuit which maybe traced-from the earth connection 7 through the-normal contactsll ofthe relay 11 to the negative pole of the line battery 6. After continuing through this battery, the circuit extends through the forward contacts .5 of

the'relay l tothe line conductor L, thereby imparting an impulse of positive currenty over the line. lince only a single impulse of negative current is desired in the assumed combination oit perlforations in the tape 214-, the relay l will only continue energized during' the time the perforation 35 may be traveling underneath the brush 36, which controls the operating circuit or the relay l. its the tape advances, the brush 31, although entering the perforation 29, which corre-r spends with an impulse of negative current, will not cause the operation of the relay 11 due to the tact that this brush controls the marginal oi'` holding Winding l2 of the relay ll. lVlien the perioration 29 comes under the brush 30, however, current from the battery 20 through the Winding 13 Will cause the operation of the relay 1l to close its torward contacts l5 and since the brushes 36 and 37, which correspond with the control of positively poled impulses to the linie L,

Vivilllbe continuing insulated by the tape,

negative current Will again be established over the contacts l5 of the relay ll and the normal contacts et ot the relay l With the line conductor L.

Lvln considering the electrical eects produced by transmission of the live impulses just described with respect to the line L, reference will be had to Fig. 2 or the drawing in which the irregular shaded line at it may be considered as indicating a series of impulse intervals corresponding with the pei'l'oiations present in the tape 24; fissuniing that these impulses may have been transmitted by the usual methods, a. current line similar to that shown by the shaded line l would have resulted with respect to the receiving end of the cable L. For conven ieiice ot description, the two dot and dash lines E, respectively, above yand below` the zero potential line O may be considered as representing the etliciency line or' the positive and negative impulses, that is, at the receiving end of the cable, it Will be necessary for the current to rise to a strength indicated by this line in order to properlyl influence the receiving devices. As indicated in this shaded current line, the rirst positive impulse Would result in a current slightly in excess of the eiliciency line, While the second and third impulses of like po` larity would merely form Waves progress ing iii an ascending scale With regard to electrically charging the line conductor. Therefore, on the fourth or negative impulse being applied to the cable, the previous positively poled current charge therein would not be sutliciently overcome to permit this negative impulse to build up to the necessary e'liiciency strength E, although he fifth impulse being of positive polarity, may

rise to a proper value as shown. The con` deiisers l5 and i6 which comprise the ratio arms of the duplex equipment serve in a n'ieasure as blocking means for preventing an excess building up oi:l current strength in' 'the cable, and serve to cause the impulses to have what may be termed more abrupt or steep Wave front. A

lluder the system the live iinvpulses illust il, would be handled bv the transmitter in a manner as may be illus'- trated by the shaded line at C, While the actual ellects oi mese currents at the receiviiig end ol: the cable may be considered as corresoondii ith the curved line shown at l). Tasse currents as received are iii 'the 'torni oit a sharp rise in current correspond ing' with the lire current impulse and this application of cuire-nt continues Without interruption through the duration ot the thro. positive impulses` the condensers l5 and lG continue charged and the resulting' effect with the cable that th current vroiiilrl L, dually vtall therein to approximately tlie zero line as shown. ivill there tore be clear that although the single Ytouifth negative impulse "follows three successive positive impulse intervals, it will not be opposed but may build up to a slightly greater strength than required by the efficiency' line li), and iii turn the iiith or positive impulse may also build up to a proper value as shown. C

The duplex equipment also comprises re-v ceiving' devices 2 7 connected from the line L to an artificial line indicated as AL and bv comparing 'the current line A (Fig. 2) with current line C or the current line with the current line l), it will lieclcar an increased number ot Wave etlferts are present bythe usual transmission methody ,fi and l, nf'l'iereby a greater number ot sur Lge lt is .vell understood in the art lrinp. conditions iny exact lulaiue of an it e .i line with respect rto real line or cable may Yt'requently exist and u rer such condition changes oit' current set up by the transmitting' devices may interfere with the e or local receiving devices, and accordnt line C and D (lv'lig. 2) which are characteristics ot the present system, will clearly reveal a material reduction in the number oit current changes therefore corresponding bettering ot the condition for the proper Working of the home receiving' devices as the device l?, mav result through the present system. L

From the foregoing description, it Will be clear that by means of the. present organization oit apparatus continuous application or current may be substituted Jfor successively recurring impulses lilre polarity. and it Will also oe clear that such intervals of. current with a line conductor may correspend in the matter ot time duration exactly ngly, inspection of the curr l under with thebeginning and ending oi a series of inipulse'intervais as represented by the perorations in a transmitting tape, i. e., at the instant controlling; brush encounters a per foration, ,urrent will be applied toa cable and such current interval will continue until such instant as thesame controlling brush may leave the last perforation in a. series ot perforations representing successive impulses of like polarity.

lllflhat is claimed is:

l. ln a telegraph system, a line, a transmitting tape, a plurality of sets of Contact brnslies.` the brushes of each set beingpositioned in tandem with respect to said tape and ccoi, erartinn` therewith to send signaling impulses to the line, the polarity of the line impulses being different for each set ot brushes, and meansl dependent upon the lonoitudinal distance between. successive perrorations in the tape for determining the duration of the transmitted impulses.

Q. n a. telegraph system, a line, an impulse transmitting device comprising a drum ot conducting material, a. perforated transmitting tape, a plurality of sets o'i contact brushes, the brushes oi each set beinga positioned in tandem with respect to said tape and arranged to malte l-ontact with said drum through pertorations'in said tape for transmitting signaling impulses to the line, the polarity ot the line impulses beingdi't'- `ferent for each set ot' brushes', and means dependent upon the longitudinal distance. between successive peritorations in the tape lor determining,v the duration ot the impulses transmitted to the line.

In a telegraph transmitting system, a line conductor, a notated transmittingv tape, a plurality o brushes positioned tandem with respect to said tape, and electroresponsive means controlled by brushes to continuously apply potential to said line during a period predetermined successive notations on said tape may be effective with the brushes.

l'n` a telegraph transmitting system, a. conductor, tape means, a pair ofl positioned tandem, with respectA to .wf er er m 1J otherwise corresponding; With 4periods dui.'- ingjivhich successive impulses of like polarity would be required.`

5. ln telegraph transmitter, a transmittiilg; tape, line'conductoi', a first pair of brushes set tandem With respect to saidtape, acompound Wound relay controlled by said brushes, a second pair ot similarly arranged brushes and a relay controlled thereby, and means controlled by each pair of said brushes to render the associated relay eifective to apply a singley interval of potential to said line in substitution of successive intervals oit current ol: like polarity.

G. ln a telegraph transmitting system, a notated tape, a line conductor, a plurality of brushes to track said tape, a compound Wound relay having/j windings respectively 1apli transmitting'v system, a

lays in applying potential toy said line conductor..

ln Witness whereof, lhereunto subscribe my name this 22nd day of November, A. D.

' i. JOHN H.y BELL.

a notated tape, a plurality.

relays 'for normally grounding said line 

